The article ‘The brain response interface: communication through visually-induced electrical brain responses”, Journal of Microcomputer Applications (1992) 15, 31-45, by Erich E. Sutter discloses an experimental communication system for severely disabled persons that utilizes electrical responses from the brain. This article describes experiments and theories with respect to detection and utilization of visual stimuli, where the stimuli comprise visual patterns displayed on a screen which are rapidly changing in time. The stimuli furthermore comply with a number of requirements and are modulated in time using pseudo-random white binary sequences.
International patent application WO2008/065239 discloses a method to determine the hearing threshold in humans. Specific auditory stimuli and analysis of the related brain response signals are used. The stimuli comprise an auditory signal having a distinct characteristic such as a ramp in frequency or intensity.
U.S. Pat. No. 5,788,648 discloses an EEG apparatus for analysis of quantified stimuli, including calculations of correlations between stimuli and brains signals.
American patent application US2005/0182456 discloses a method of cortical mapping, wherein subcutaneous electrodes are used to generate stimuli directly to brain cell areas, and electromyography is used to measure responses to those stimuli.
International patent application WO2008/025048 discloses a method and device for controlling equipment with the aid of electro-encephalograms (EEG) or electro-corticograms (ECoG). For this, different periodic stimuli are generated, each with a given base frequency. These periodic stimuli (frequency tagged stimuli) can be detected in the EEG or ECoG signals, amongst other by synchronizing the generation of stimuli and detection in the signal processing.
International patent application WO94/17730 discloses thought analysis from brain wave data, such as EEG signals. Use is made of conceptual interpreters, whereby a test subject is presented with conceptual information and background stimuli. The brain wave data is subjected to signal processing using a stimulus model which represents attributes of stimuli.